U.S. patent number 5,086,243 [Application Number 07/568,357] was granted by the patent office on 1992-02-04 for rotation detector for a commutator motor excited by pole units.
This patent grant is currently assigned to Siemens Aktiengesellschaft. Invention is credited to Manfred Hofmann.
United States Patent |
5,086,243 |
Hofmann |
February 4, 1992 |
Rotation detector for a commutator motor excited by pole units
Abstract
A rotation detector has a one-piece universal brush rocker that
includes a supporting body that is injection molded, particularly
out of plastic. The measuring coil is held on the supporting body
between the pole gaps of pole units on the stator side and the
measuring coil's winding ends connected to the stripped ends of the
brush shunts are cast in the universal brush rocker. This rotation
detector guarantees a contacting between the winding ends of the
measuring coil and the brush shunts retained on the brush rocker of
the commutator motor, and features ease of assembly and lasting
operational reliability.
Inventors: |
Hofmann; Manfred (Hettstadt,
DE) |
Assignee: |
Siemens Aktiengesellschaft
(Berlin & Munich, DE)
|
Family
ID: |
8201804 |
Appl.
No.: |
07/568,357 |
Filed: |
August 15, 1990 |
Foreign Application Priority Data
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Aug 25, 1989 [EP] |
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89115738.0 |
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Current U.S.
Class: |
310/68B; 310/239;
310/249; 310/406; 310/43; 310/71; 324/207.15 |
Current CPC
Class: |
B60T
8/4022 (20130101); H02K 5/10 (20130101); H02K
11/225 (20160101); H02K 5/225 (20130101); H02K
23/66 (20130101); H02K 5/143 (20130101) |
Current International
Class: |
B60T
8/40 (20060101); H02K 5/10 (20060101); H02K
23/66 (20060101); H02K 5/22 (20060101); H02K
11/00 (20060101); H02K 5/14 (20060101); H02K
011/00 () |
Field of
Search: |
;310/68B,171,42,43,154,239,249,233,71
;324/173,174,207.15,207.16,207.25 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0235443 |
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Sep 1987 |
|
EP |
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0307709 |
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Mar 1989 |
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EP |
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3502442 |
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Jul 1986 |
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DE |
|
2039420 |
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Aug 1980 |
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GB |
|
Primary Examiner: Skudy; R.
Attorney, Agent or Firm: Kenyon & Kenyon
Claims
What is claimed is:
1. A rotation detector for use in a commutator motor having at
least two pole units separated by pole gaps comprising:
a one-piece injection molded universal brush rocker including a
supporting body of a size to fit in the pole gaps between two said
pole units;
a measuring coil disposed in said supporting body;
brush shunts supported by said brush rocker; and
winding terminations leading from said measuring coil to said brush
shunts.
2. The rotation detector according to claim 1, wherein said
measuring coil is integrally cast in said universal brush
rocker.
3. The rotation detector according to claim 1, further comprising a
measuring coil core, wherein said measuring coil is wound around
said measuring coil core and said measuring coil and said measuring
coil core are integrally cast in said universal brush rocker.
4. The rotation detector according to claim 3 wherein the brush
shunts have stripped ends and said winding terminations of said
measuring coil are wound around said stripped ends.
5. The rotation detector according to claim 2 wherein the brush
shunts have stripped ends and said winding terminations of said
measuring coil are wound around said stripped ends.
6. The rotation detector according to claim 3 wherein the brush
shunts have stripped ends and said winding terminations of said
measuring coil are wound around said stripped ends.
7. The rotation detector according to claim 1 wherein the brush
shunts have stripped ends and said winding terminations of said
measuring coil are-soldered to said stripped ends.
8. The rotation detector according to claim 2 wherein the brush
shunts have stripped ends and said winding terminations of said
measuring coil are soldered to said stripped ends.
9. The rotation detector according to claim 3 wherein the brush
shunts have stripped ends and said winding terminations of said
measuring coil are soldered to said stripped ends.
10. The rotation detector according to claim 1 wherein the brush
shunts have stripped ends and said winding terminations of said
measuring coil are wound around said stripped ends and soldered to
said stripped ends.
11. The rotation detector according to claim 2 wherein the brush
shunts have stripped ends and said winding terminations of said
measuring coil are wound around said stripped ends and soldered to
said stripped ends.
12. The rotation detector according to claim 3 wherein the brush
shunts have stripped ends and said winding terminations of said
measuring coil are wound around said stripped ends and soldered to
said stripped ends.
13. A rotation detector according to claim 4, wherein said winding
terminations of said measuring coil and said stripped ends of the
brush shunts are integrally cast in said universal brush rocker so
that said winding terminations and said stripped ends are insulated
from each other.
14. A rotation detector according to claim 7, wherein said winding
terminations of said measuring coil and said stripped ends of the
brush shunts are integrally cast in the universal brush rocker so
that said winding terminations and said stripped ends are insulated
from each other.
15. A rotation detector according to claim 10, wherein said winding
terminations of said measuring coil and said stripped ends of the
brush shunts are integrally cast in the universal brush rocker so
that said winding terminations and said stripped ends are
insulated.
16. The rotation detector according to claim 2, wherein said
universal brush rocker and cast measuring coil are shaped to form a
slide-in part which can be introduced into the pole gap.
Description
BACKGROUND OF THE INVENTION
This invention relates generally to rotation detectors for
commutator motors excited by pole units, and more particularly to
an improved measuring coil for such a rotation detector
A rotation detector for this type of commutator motor, which has a
measuring coil mounted in at least one pole gap between the pole
units on a supporting body, particularly one made of plastic, and
which has winding terminations that are connected to brush shunts
held on the brush rocker of the commutator is disclosed in EP-Al-0
307 709. As disclosed therein, a measuring coil is mounted in at
least one pole gap between the pole units which may be
partial-shell magnets or unit exciter poles. A current can be
induced in the measuring coil by the pulsing of the stray field
resulting in a current that has a slot-ripple frequency during the
rotation of the rotor. This measuring coil is retained in a
non-magnetic supporting body, particularly one made of plastic,
which can be inserted between the partial-shell magnets or the unit
exciter poles. The measuring coil is wound around an induction iron
core, whose tangential extension is preferably smaller than the
width of the slot opening and the tooth space of the slotted and
toothed rotor respectively. The measuring coil and/or the induction
iron core are inserted in pockets of the supporting body and
preferably retained in these pockets by a locking fastener. The
supporting body has measuring coil terminals for coupling to
external leads. The inside ends of these terminals are coupled to
the measuring coil. The external measuring coil terminals of the
supporting body are able to be contacted by corresponding mating
terminals for brush rocker shunts on a brush rocker. The supporting
body that accommodates the external measuring coil terminals is
designed as a discrete component in the assembly of the commutator
motor. Likewise, the brush rocker is designed and mounted as a
discrete component. This type of rotation detector is difficult to
assemble and does not make a sufficiently reliable contact between
the winding ends of the measuring coil and the brush shunts
retained on the brush rocker of the commutator motor.
In view of this, the present invention is directed to the problem
of further developing a rotation detector device which enables
greater ease of assembly and more reliable contact between the
winding ends of the measuring coil, on the one hand, and the brush
shunts retained on the brush rocker of the commutator motor, on the
other hand.
SUMMARY OF THE INVENTION
According to the present invention, in a commutator motor of the
type described above, the universal brush rocker is a one piece
unit that also includes the supporting body for the measuring coil,
that is injection molded, particularly out of plastic. This
component is then able to be inserted between the pole gaps in one
assembly operation with a connection at the common holding part.
The connection is capable of reliable preliminary contact between
the winding ends of the measuring coil and the brush shunts. Then a
simple reliable contact is made in a way which requires less
engineering complexity. The measuring coil and/or the measuring
coil induction core associated with the measuring coil, and the
measuring coil winding ends, and the stripped ends of the internal
brush shunts, are integrally cast as an insertion part in the
universal brush rocker so that the winding ends and the stripped
ends are insulated from each other. For contacting purposes, the
stripped ends of the internal brush shunts have these measuring
coil winding ends wound around and possibly soldered to them.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial, longitudinal, sectional view of a commutator
motor constructed according to the principles of the invention with
a one-piece universal brush rocker, which accommodates both the
brush apparatus as well as the measuring coil apparatus.
FIG. 1a is a sectional view showing the stripped ends of the brush
shunts and winding terminations of the measuring coil wound around
the stripped ends.
FIG. 2 the device of FIG. 1 in a sectional view sectional path
II--II.
FIG. 3 is the device of FIG. 1 in a sectional view according to
sectional path III--III.
DETAILED DESCRIPTION
Referring to FIG. 1, a permanent magnet excited, direct-current,
low power motor is depicted with two partial-shell magnets 6 and 7.
These two partial-shell magnets form corresponding pole gaps at the
inner circumferential surface of a stator housing 1. The motor has
a rotor, which is indicated in FIG. 1 only by a rotor shaft 2. The
motor also has a commutator 21 and a slotted rotor laminated core
on which a rotor armature is wound. The partial-shell magnets 6 and
7 are braced against each other at the circumferential surface of
the stator housing 1 by means of fastening springs 8 and 9, also
visible in FIG. 2. The fastening springs are inserted in the pole
gaps between the end surfaces of the magnets, which are open
towards the axial front end of the motor.
Referring to FIG. 2, a plastic supporting body 31, which
accommodates a measuring coil induction core 5 with a measuring
coil 4 wound around it, is mounted in the inner circumferential
space of a fastening spring 8. The plastic supporting body 31 as
shown in FIG. 1, is part of the one-piece universal brush rocker 3.
The universal brush rocker 3 is inserted as a brush plate at the
right front end of the stator housing 1 between the housing and an
end shield 11. The universal brush rocker 3 has an axially
protruding part which projects into the pole gap in which spring 8
in located and includes the plastic supporting body 31. The
universal brush rocker 3 includes inter alia mounting supports 33
for securing hammer brush holders 34. The brushes 35 are attached
to the free ends of the hammer brush holders 34 and contact the
surface of the commutator 21.
The one-piece universal brush rocker 3 with the extruded plastic
supporting body 31 is a preassembled part, with the measuring coil
4 and the measuring coil induction core 5, and all brush components
on the stator side and in its preassembled form includes all
internal electrical connections.
The terminals of the measuring coil 4 formed by winding ends 41 are
connected inside the universal brush rocker 3 to the brush shunts
32. Brush shunts 32 include outer terminals brought out by means of
a sealing bushing 37. Brush shunts 36, used for the voltage supply
of the motor winding of the commutator motor, are brought out in a
similar manner.
The brush shunts 32 are joined to the winding ends 41 of the
measuring coil 4 and form a measuring line. The brush shunts 32
transmit signals from the measuring coil winding ends 41. The brush
shunts 32 lead either to an internal rotation detection circuit and
control system, on the universal brush rocker 3 itself or--as in
the present embodiment--to the outside, to an external detection
circuit and control system.
To ensure a simple and reliable contact between the measuring coil
winding ends 41 and the brush shunts 32, the winding ends 41 of the
measuring coil 4 are wound around the stripped ends of the internal
brush shunts 32 (FIG. 1a ), possibly soldered to these brush shunts
32 and, in an advantageous way, integrally cast as an insertion
part in the universal brush rocker 3, so that the winding ends and
the stripped ends are both insulated. Additionally, the universal
brush rocker and cast measuring coil can be shaped such that they
form a slide-in part which can be introduced into the pole gap.
* * * * *